Search Results (113)

Acute ischemic stroke (AIS) is a leading cause of disability and death worldwide, requiring rapid reperfusion to minimize damage. Current treatments, including intravenous thrombolysis (IVT) with alteplase (rt-PA) and mechanical thrombectomy (MT), face limitations such as thrombolysis resistance, dosing complexity, and reduced efficacy in large vessel occlusions (LVOs) or fibrin-rich clots. Tenecteplase (TNK), a bioengineered thrombolytic agent with superior pharmacokinetics, simplified administration, and higher fibrin specificity, offers promising advantages over rt-PA, including potential synergy with MT and efficacy against resistant thrombi. Direct oral anticoagulants (DOACs) further complicate AIS management, but evidence suggests that DOAC-treated patients may experience better thrombolysis outcomes due to distinct thrombus characteristics. Advances in imaging now enable precise visualization of vessel occlusion and treatment effects, opening opportunities to refine therapies. Combination approaches targeting fibrin thrombus components may enhance thrombolysis and improve outcomes in resistant cases. Future research should explore TNK’s role in intra-arterial (IA) applications, combination therapies, and its interaction with MT to optimize reperfusion strategies. TNK’s simplified use and promising efficacy position it as a potential breakthrough in AIS management, with the potential to improve functional recovery and reduce treatment complexity. Full article

Traditional anticoagulants used in atrial fibrillation (AF) are being increasingly replaced by novel oral anticoagulants such as rivaroxaban, improving patient outcomes. Although rivaroxaban 20 mg/1× daily is approved to reduce stroke and systemic embolism risk in AF, some patients still develop thrombus in the left atrial appendage (LAA). A previous study demonstrated thrombus lysis with a modified regimen of rivaroxaban 15 mg/2× daily, yet over 50% of patients remained unresponsive despite therapeutic plasma levels. This study compared metabolic profiles of responders and non-responders to identify predictive markers of treatment efficacy. From the RIVA-TWICE study cohort (n = 249), 15 AF patients with LAA thrombus despite standard dosing were switched to 2 × 15 mg rivaroxaban. Plasma samples collected prior to dose modification underwent untargeted and targeted LC-MS analysis, focusing on acylcarnitines (ACs), carnitine, and its precursors. Thrombus resolution occurred in 7 (46.7%) patients, who showed differential abundance of metabolites related to alpha-linolenic acid and fatty acid metabolism, carnitine synthesis, and arginine/proline pathways. Targeted analysis confirmed elevated levels of ACs, carnitine, and precursors. Findings suggest that a patient phenotype, including carnitine, its precursors, and ACs, may predict rivaroxaban efficacy in thrombus lysis. While these metabolites may not directly mediate lysis, their elevated levels represent potential biomarkers of treatment response. Full article

Maintaining redox balance is essential for platelet physiology and overall cellular homeostasis. Upon activation, platelets generate reactive oxygen species (ROS), which act as signaling mediators in responses to collagen and are required for collagen-dependent thrombus formation. Multiple enzymatic systems contribute to platelet ROS production, with nicotinamide adenine dinucleotide (phosphate) oxidases (NOX isoforms) serving as the primary source, complemented by cyclooxygenase (COX), xanthine oxidase (XO), and the mitochondrial respiratory chain. Both oxidative and reductive stress disrupt this equilibrium and have been implicated in the pathophysiology of diverse diseases, including bleeding disorders, thrombosis, cardiovascular disorders, diabetes and cancer. In transfusion medicine, mitochondrial dysfunction and the resulting oxidative stress are key drivers of platelet lesion resulting in clearance defects and the progressive loss of hemostatic activity during storage. Targeting platelet-specific redox regulatory pathways represents a promising strategy to better define platelet contributions to human health and to develop interventions that may alter disease outcomes in which platelets play a central role. Full article

The development of effective anticoagulants remains a critical need in modern medicine, particularly for preventing and treating thromboembolic disorders, such as arterial thrombosis and deep vein thrombosis (DVT), as well as complications like ischemic stroke. This study identifies a cysteine-knotted peptide GC38 (sequence: GCSGKGARCAPSKCCSGLSCGRHGGNMYKSCEWNWKTG) derived from the venom gland transcriptome of the Macrothele sp. spider, which exerts thrombus-inhibitory effects by potentiating activated protein C (APC) activity. In vitro assays reveal that GC38 enhances APC activity, prolongs plasma clotting time, and shows no significant cytotoxicity or hemolytic activity. Mechanistically, GC38 interacts allosterically with APC; biolayer interferometry (BLI) confirms this direct interaction, with a dissociation constant K_D of 6.16 μM. Additionally, three in vivo thrombosis models (FeCl₃-induced arterial occlusion, stasis-induced DVT, and cortical photothrombotic stroke) consistently demonstrated that GC38 was effective in alleviating thrombus formation, with tail-bleeding assays confirming its low hemorrhagic risk. Collectively, our findings position GC38 as a pioneering spider venom-derived lead molecule that addresses dual arterial and venous antithrombotic actions. This opens new avenues for developing spider venom-derived peptides as therapeutic agents targeting intravascular coagulation in arteries and veins. Full article

Background/Objectives: Eosinophilic myocarditis (EM) is a rare, life-threatening inflammatory cardiomyopathy driven by eosinophil cytotoxicity and extracellular trap formation. Interleukin-5 (IL-5) inhibition may disrupt this pathogenic cascade. We reviewed contemporary evidence on IL-5 blockade in EM and contextualized it with an illustrative case. Methods: We searched PubMed through May 2025 for reports of EM treated with mepolizumab or benralizumab. Inclusion criteria were consistent with prior cohorts: acute cardiac symptoms with biomarker elevation plus abnormalities on transthoracic echocardiography and/or cardiac magnetic resonance imaging (CMR), along with documented IL-5-targeted therapy. We extracted clinical, imaging, biopsy, treatment-timing, and outcome data and included one institutional case. Results: Twenty-one episodes were analyzed (median age, 45 years; 10 men). Underlying conditions included eosinophilic granulomatosis with polyangiitis (10 cases; 48%), hypereosinophilic syndrome (5 cases; 24%), drug reaction with eosinophilia and systemic symptoms (DRESS, 3 cases; 14%), and eosinophilic asthma (3 cases; 14%). Treatments involved mepolizumab in 17 cases (81%) and benralizumab in 4 (19%); 4 patients received “early-start” therapy within 14 days of EM diagnosis. Among the 11 episodes with reported left ventricular ejection fraction (LVEF) at baseline and follow-up, the median baseline LVEF was 40% (range, 30–62), with 10 of 11 (91%) <50%. On follow-up, all 11 patients improved: 4 normalized (≥50%) and 7 improved to 40–49%. CMR (n = 18) demonstrated late gadolinium enhancement in 14 cases (78%), edema in 9 (50%), and intracardiac thrombus in 4 (22%). Endomyocardial biopsy confirmed eosinophilic infiltration in 13 of 15 cases (87%). Outcomes included one death (fulminant DRESS), one recovery following veno-arterial extracorporeal membrane oxygenation, and one successful heart transplantation. Illustrative case: A 24-year-old man on a steroid taper received mepolizumab 300 mg on Day 4. His LVEF improved from 47% to 59% by Day 15, accompanied by biomarker decline and successful steroid tapering. Conclusions: Across published cases and our institutional experience, IL-5–targeted therapy appears safe, steroid-sparing, and associated with rapid ventricular recovery, particularly when initiated early. Although limited, these findings support the need for prospective trials to define the optimal agent, dosing, timing, and integration with standard immunosuppression and anticoagulation. Full article

Apolipoprotein C3 (apoC3) is a key regulator of triglyceride metabolism and has emerged as a potential therapeutic target for reducing the risk of cardiovascular disease. However, its broader physiological functions are not fully understood. This study investigates the role of apoC3 in platelet function and thrombus formation. Interestingly, human apoC3 was found to rapidly inhibit platelet activation over the tested concentration range of 0.1–10 µg/mL, with significant effects observed at low concentrations and brief pre-incubation times (from 1 min). At a concentration of 10 µg/mL, apoC3 suppressed platelet activation by approximately 70% in response to ADP and by approximately 40% in response to collagen stimulation. Depleting apoC3 from human serum enhanced platelet aggregation by more than 25 % (1.28 ± 0.19 vs. vehicle), indicating an endogenous regulatory function of apoC3. Mechanistically, apoC3 binding to platelets reduced both GPIIb/IIIa activation and P-selectin expression by around 20%. ApoC3 binding to platelets increased when platelets were activated by ADP and was partially mediated by GPIIb/IIIa, implicating this integrin as a functionally relevant receptor. Taken together, these findings reveal a novel link between apoC3 and platelet biology with potential implications for thrombotic risk and vascular homeostasis. Full article

Background: The treatment landscape for advanced hepatocellular carcinoma (HCC) has evolved significantly recently; however, access to novel agents remains limited because of high costs. This study aimed to evaluate the systemic treatment patterns and survival outcomes for advanced HCC across different systemic treatment sequences under real-world resource constraints. Methods: This retrospective study was conducted at a tertiary center in Southern Thailand. The medical records of patients (n = 330) with advanced HCC treated with systemic therapy between 2010 and 2024 were reviewed. Outcomes included overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Prognostic factors for OS were investigated. Results: First-line therapies included tyrosine kinase inhibitor (TKI; 69.7%), chemotherapy (23.3%), immunotherapy (IO)/targeted therapy (3.6%), dual IO (1.8%), and IO monotherapy (1.5%). The median OS, PFS, and ORR for each cohort were 7.2, 5.2, 10.9, 8.5, and 8.6 months; 3.94, 3.22, 3.48, 6.19, and 2.69 months; and 9.6%, 10.4%, 16.7%, 0%, and 20.0%, respectively. OS improved with increasing lines of therapy (4.5, 12.2, 19.4, and 40.7 months for one to four lines, respectively). Portal vein tumor thrombus, ascites, elevated bilirubin level, high alpha-fetoprotein level, and poor Eastern Cooperative Oncology Group performance status were associated with poor prognosis; multiple treatment lines and overweight status were associated with improved OS. Conclusions: In this large real-world cohort, TKIs remained the mainstay effective treatment option because of limited access to IO-based regimens. Sequential systemic therapy significantly improved survival, emphasizing the importance of preserving treatment eligibility and multidisciplinary team involvement. Chemotherapy could be considered a viable option in resource-limited settings. Full article

Soluble CD40 ligand (sCD40L) is a molecule known for its thromboinflammatory properties and may act as a biomarker for platelet activation. Platelets are the principal producers of sCD40L, which is recognized for its impact on platelet function. However, its contribution to the platelet hyperreactivity observed in SARS-CoV-2 infection remains poorly understood. During viral infection, platelets function as crucial intermediaries, engaging with both viruses and leukocytes; and serve as a substantial source of inflammatory mediators, promoting thromboinflammation and immunothrombosis. While platelet hyperactivation is associated with the severity and mortality of COVID-19, the precise function of sCD40L in this setting remains inadequately defined. This study examined the role of platelet-derived sCD40L in platelet activation, aggregation, and thrombosis associated with COVID-19. Platelets from blood samples of 160 patients—102 with non-severe cases and 58 with severe cases—demonstrated heightened activation and aggregation, as well as elevated sCD40L release. In a mouse thrombosis model, sCD40L intensified thrombus development. These findings underscore the essential function of platelet-derived sCD40L in the pathophysiology of COVID-19 and endorse the therapeutic potential of targeting CD40L-mediated pathways to mitigate thromboinflammatory consequences. Full article

Despite the prevalence of fucosylated IgG in plasma, specific IgGs with low core fucosylation sporadically emerge in response to virus infections and blood cell alloantigens. This low fucosylation of IgG is implicated in the pathogenesis of SARS-CoV-2 and dengue infections. In COVID-19, the presence of IgGs with low core fucosylation (afucosylated IgGs) targeting spike protein predicts disease progression to a severe form and actively mediates this progression. This study reveals that SARS-CoV-2 infection of megakaryocytes promotes the generation of pathogenic afucosylated anti-spike IgGs, leading to outcomes, such as pulmonary vascular thrombosis, acute lung injury, and mortality in FcγRIIa-transgenic mice. Platelets from mice injected with virus-infected human megakaryocytes express significant activation biomarkers, indicating a direct link between the immune response and platelet activation. Mice injected with virus-infected human megakaryocytes demonstrate an elevated rate of thrombus formation induced by FeCl₃ (4%) and a reduction in bleeding time, emphasizing the intricate interplay of viral infection, immune response, and hemostatic complications. Treatment with inhibitors targeting FcγRIIa, serotonin, or complement anaphylatoxins of mice injected with spike-expressing MKs successfully prevents observed platelet activation, thrombus formation, and bleeding abnormalities, offering potential therapeutic strategies for managing severe outcomes associated with afucosylated IgGs in COVID-19 and related disorders. Full article

Procoagulant platelets are a specialized subset of activated platelets that externalize phosphatidylserine (PS) on their surface, facilitating the assembly of tenase and prothrombinase complexes and enhancing thrombin generation and clot formation. Although procoagulant platelet formation shares certain features with nucleated cell death pathways, such as mitochondrial dysfunction, calcium (Ca²⁺) overload, membrane blebbing, and microvesiculation, it differs in key molecular mechanisms, notably lacking nuclei and caspase-dependent deoxyribonucleic acid (DNA) fragmentation. Interestingly, molecular components of nucleated cell death pathways in platelets can promote thrombus formation without impacting platelet lifespan. Under pathological conditions, excessive platelet activation may result in platelet lysis, resembling the complete activation of nucleated cell death pathways and contribute to thrombocytopenia. This review compares procoagulant platelet formation with various nucleated cell death pathways, including necrosis, necroptosis, pyroptosis, and ferroptosis, and explores their role in pathological thrombosis and blood clotting. A deeper understanding of mechanisms may help in developing targeted therapies to prevent aberrant blood clotting, platelet death and thrombocytopenia. Full article

Background: Venous sinus stenting is a promising treatment for intracranial venous disorders, such as idiopathic intracranial hypertension and pulsatile tinnitus, associated with transverse sinus stenosis. The VIVA Stent System (VSS) is a novel self-expanding braided venous stent designed to navigate tortuous cerebral venous anatomy. This preclinical study assessed the safety, thrombogenicity, and performance of the VSS in a swine model. Methods: Fifteen swine underwent bilateral internal mammary vein stenting with either the VSS (n = 9) or the PRECISE^® PRO RX stent (n = 6, reference). Fluoroscopy and thrombogenicity assessments were conducted on the day of stenting, clinical pathology analysis was carried out throughout the in-life phase, and CT Venography was performed before sacrifice. Animals were sacrificed at 30 ± 3 or 180 ± 11 days post-stenting for necropsy and histological evaluation. Results: Fluoroscopic angiography confirmed the successful VSS deployment with complete venous wall apposition and no vessel damage. The VSS achieved the highest scores on a four-point Likert scale for most performance parameters. No thrombus formation was observed on either delivery system. CT Venography confirmed vessel patency, no stent migration, and complete stent integrity. Histopathology showed a mild, expected foreign body reaction at 30 days, which resolved by 180 days, indicating normal healing progression. Both stents showed increased luminal diameter and decreased wall thickness at 180 days, suggesting vessel recovery. No adverse reactions were observed in non-target organs. Conclusions: The VSS exhibited favorable safety, procedural performance, and thromboresistance in a swine model, supporting its potential clinical use for treating transverse sinus stenosis and related conditions. Full article

Inflammation contributes to myocardial injury in ST-elevation myocardial infarction (STEMI). Interleukin-6 receptor (IL-6R) inhibition has been shown to mitigate myocardial injury and reduce levels of the prothrombotic and inflammatory mediator, neutrophil extracellular traps (NETs). The enzyme peptidylarginine deiminase 4 (PAD4) is central in NET formation. We hypothesized that PAD4 links IL-6R activation and NET formation. Methods: We conducted thrombus aspiration and peripheral blood sampling in 33 STEMI patients. In thrombi and leukocytes, we quantified the mRNA of IL-6, IL-6R, and PAD4. In peripheral blood, the protein levels of IL-6, IL-6R, PAD4, dsDNA, H3Cit, MPO-DNA, and troponin T were quantified. Results: In thrombi and circulating leukocytes, PAD4 mRNA was associated with IL-6R mRNA (thrombi: β = 0.34, 95% CI [0.16–0.53], p = 0.001, circulating leukocytes: β = 0.92, 95% CI [0.07–1.77], p = 0.036). There were no correlations between PAD4 and IL-6 in thrombi and leukocytes. The protein levels of IL-6R were associated with the NET marker H3Cit (r_s = 0.40, p = 0.02). In thrombi, PAD4 mRNA was associated with high levels of troponin T (β = 1.15 95% CI [0.27–2.04], p = 0.013). Conclusion: We demonstrate an association between PAD4, IL-6R, and troponin release in STEMI patients. Our findings indicate a PAD4-mediated connection between IL-6R and NET formation and highlight PAD4 as a potential treatment target for mitigating inflammation and myocardial injury in STEMI. Full article

Current αIIbβ3 antagonists are potent antithrombotic agents, their clinical use is limited by the risk of life-threatening bleeding. Emerging evidence has highlighted key mechanistic differences between thrombosis and hemostasis, opening avenues for safer antithrombotic strategies. Targeting integrin αIIbβ3 outside-in signaling has been proposed to mitigate bleeding risk; however, the short half-life of peptide-based therapeutics remains a major challenge. In this study, we developed an optimized αIIbβ3 antagonist, KGDRR—a recombinant mutant protein derived from snake venom disintegrin, incorporating an Arg55 residue within the KGD loop—through systematic structure–activity relationship (SAR) analysis. Molecular docking revealed a critical cation–π interaction between Arg55 of KGDRR and Tyr122 of the β3 subunit, stabilizing integrin αIIbβ3 in an unliganded-closed conformation. Functionally, KGDRR selectively inhibited thrombus propagation by blocking ligand binding and downstream Gα13-mediated outside-in signaling while preserving initial thrombus core formation, which is a limitation of current αIIbβ3 inhibitors. Unlike conventional antagonists, KGDRR maintained αIIbβ3 in an unliganded-closed conformation without inducing the integrin activation and conformational change that lead to immune-mediated platelet clearance and thrombocytopenia. In animal models, KGDRR effectively suppressed thrombus growth without causing thrombocytopenia or prolonging bleeding time. Furthermore, intramuscular administration of KGDRR achieved a functional half-life 3.5 times longer than that of the clinically used antithrombotic eptifibatide at equivalent antithrombotic efficacy. In conclusion, KGDRR exhibits potent antithrombotic activity with a favorable safety profile and enhanced pharmacokinetic stability. These findings position KGDRR as a promising next generation αIIbβ3 antagonist with the potential to improve clinical outcomes in antithrombotic therapy. Full article

Platelet activation processes begin when injury to blood vessels exposes the subendothelial matrix, leading platelets to attach to it, where they become activated and exert their hemostatic function. Excessive platelet aggregation is associated with thrombotic disorders such as arterial thrombosis. To manage such diseases, medications that inhibit thrombosis are continuously sought, despite potential drawbacks that include hemorrhage. This study described the development of a novel peptide-based vaccine that targets the purinergic ADP P2Y₁ receptor (abbreviated EL2Vac) and its pharmacological characterization. Thus, we designed and developed an EL2Vac that targets the ligand-binding domain of the P2Y₁ receptor protein, which is located in its second extracellular loop (EL2). We then evaluated the vaccine’s ability to trigger an immune response (antibody production) in immunized mice, modulate platelet function, its antithrombotic activity, and any effects on hemostasis, by employing a thrombosis model and the tail bleeding time assay. Results showed significant levels of antibody production in mice treated with EL2Vac, in comparison with the random peptide vaccine control (EL2rVac), which persisted at least up to six months post vaccination. Moreover, we observed significant inhibition of the ADP-induced aggregation response in platelets from EL2Vac-treated mice, relative to those from EL2rVac controls. This inhibition was selective for ADP, as other agonists, such as the thromboxane A₂ receptor (TPR) agonist U46619 or high-dose collagen, had no detectable effect on aggregation. As for its capacity to protect against thrombosis, our data showed a significant delay in the occlusion time of the EL2Vac mice when compared with the random peptide control vaccine, which was also observed (at least) six months post vaccination. Interestingly, EL2Vac did not appear to prolong the tail bleeding time, supporting the notion that it is devoid of a bleeding diathesis. As a conclusion, this study documents the design and evaluation of a novel peptide-based vaccine, EL2Vac, which appears to selectively target the P2Y₁ receptor and protect against thrombus formation without impairing hemostasis. Thus, EL2Vac may provide a promising clinical option to treat thromboembolic disorders. Full article

This review aims to analyze the role of heat shock protein 47 (HSP47) in thrombosis and evaluate its potential as a therapeutic target for deep vein thrombosis (DVT). A systematic literature review was conducted using PubMed, Scopus, and Web of Science to identify studies on HSP47, thrombosis, and collagen, selecting only relevant and methodologically rigorous articles. HSP47 regulates platelet function and collagen interaction, playing a key role in deep vein thrombosis (DVT). HSP47, known for stabilizing collagen, also improves platelet–collagen binding and thrombus formation. In addition, reduced HSP47 levels reduce platelet adhesion, resulting in reduced thrombus formation, while inhibitors that target HSP47 decrease platelet aggregation in animal models. Naturally low levels of HSP47 during prolonged immobility are also found in hibernating mammals, such as bears, and are associated with reduced formation of thrombi, indicating a possible natural mechanism of thrombo-protection. This observation could inform new therapeutic approaches. Current studies use in vitro platelet aggregation assays, flow chamber assays, and collagen binding studies to investigate the role of HSP47 in clotting. This review aims to synthesize existing evidence to better understand HSP47’s role in clot formation and explore its potential as a target for novel DVT therapies. Full article